RTSP is an application-level protocol for control over the delivery of data with real-time properties.
RTSP provides an extensible framework to enable controlled, on-demand delivery of real-time data, such as audio and video.
Sources of data can include both live data feeds and stored clips.
This protocol is intended to control multiple data delivery sessions, provide a means for choosing delivery
channels such as UDP, multicast UDP and TCP, and provide a means for choosing delivery mechanisms based upon RTP.

RTSP is a text based protocol and uses the ISO 10646 character set in UTF-8 encoding.
Lines are terminated by CRLF, but receivers should be prepared to also interpret CR and LF by themselves as line terminators.

Aggregate control.
(RFC 2326)
The control of the multiple streams using a single timeline by the server.
For audio/video feeds, this means that the client may issue a single play or pause message to control both the audio and video feeds.

Continuous media.
(RFC 2326)
Data where there is a timing relationship between source and sink;
that is, the sink must reproduce the timing relationship that existed at the source.
The most common examples of continuous media are audio and motion video.
Continuous media can be real-time (interactive), where there is a "tight" timing relationship between
source and sink, or streaming (playback), where the relationship is less strict.

Media stream.
(RFC 2326)
A single media instance, e.g., an audio stream or a video stream as well as a single whiteboard or shared application group.
When using RTP, a stream consists of all RTP and RTCP packets created by a source within an RTP session.
This is equivalent to the definition of a DSM-CC stream.